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Jitter -- How low is low? - Page 2

post #16 of 151
Let's not forget the frequency and distribution matter. Quantity alone is just one variable.
post #17 of 151
Quote:
Originally Posted by 883dave View Post
....that at present we can measure or know about
No, it's a logical impossibility for anything to go faster than the speed of light based on current physical theories which have been shown to be accurate to very very small margins of error. It's not a matter of not having discovered anything. It's a simple consequence of the mathematics that it can't happen.

One can say that nothing goes faster than light as surely as one can say if you let go of something on Earth it'll fall.

</physics nerd>
post #18 of 151
Quote:
Originally Posted by monolith View Post
One can say that nothing goes faster than light as surely as one can say if you let go of something on Earth it'll fall.
An unfortunate assumption on your part. Once they let go of an Arian rocket or the space shuttle, those things end up leaving earth. Letting go of helium also doesn't result in it falling to earth.
post #19 of 151
Low is plus or minus 0.1 Parts per million. See for example the specs on the Esoteric Master Clocks.
post #20 of 151
Quote:
Originally Posted by monolith View Post
No, it's a logical impossibility for anything to go faster than the speed of light based on current physical theories...
Current physical theories rely on "dark matter" to explain galaxy movements because otherwise our calculations are WAY off. Current theories are wrong.
post #21 of 151
The people who know, the ones that on a daily bases mod cdplayers, say that if you use a good reclocking system yoú'll get better transparency/detail. So the recording will be cleaner and you can look deeper into the recording. Notes that were hiding behind other instruments or not that obvious, become much more obvious and have their own presence, all instruments and notes are much easier to follow, with better seperation.

Ask people who installed the reclocking systems and you'll know.
post #22 of 151
Quote:
Originally Posted by BigEat View Post
Low is plus or minus 0.1 Parts per million. See for example the specs on the Esoteric Master Clocks.
Most popular reclocking systems are in terms of 2-3pps. This is far and beyond the popular threshold of 150pps.
post #23 of 151
Quote:
Originally Posted by monolith View Post
No, it's a logical impossibility for anything to go faster than the speed of light based on current physical theories which have been shown to be accurate to very very small margins of error. It's not a matter of not having discovered anything. It's a simple consequence of the mathematics that it can't happen.

One can say that nothing goes faster than light as surely as one can say if you let go of something on Earth it'll fall.

</physics nerd>
I said "that at present we can measure or know about"

You said based on current physical """THEORIES"""

Throughout history man has been so arrogant as to believe he knows everything, only to be proved time and time he was wrong
post #24 of 151
Why can't someone conduct a study into the audibility of things such as jitter and settle it properly in a scientific fashion? This kind of debating is pointless.
post #25 of 151
Quote:
Originally Posted by Jingo Lingo View Post
Why can't someone conduct a study into the audibility of things such as jitter and settle it properly in a scientific fashion? This kind of debating is pointless.
This has been done.

Detection threshold for distortions due to jitter on digital audio
Kaoru Ashihara, Shogo Kiryu, Nobuo Koizumi, Akira Nishimura,
Juro Ohga, Masaki Sawaguchi and Shokichiro Yoshikawa

E. Benjamin and B. Gannon, ‘‘Theoretical and audible effects of
jitter on digital audio quality,’’ Preprint of the 105th AES
Convention, #4826 (1998).

K. Ashihara and S. Kiryu, ‘‘Simulation of sound degradation
due to time jitter on digital audio,’’ J. Acoust. Soc. Jpn. (J), 58,
232–238 (2002).

K. Ashihara and S. Kiryu, ‘‘The maximum permissible size and
detection threshold of time jitter on digital audio,’’ J. Acoust.
Soc. Jpn. (J), 59, 241–249 (2003).

T. Tomizawa, H. Ohtake and J. Ohga, ‘‘Effect of jitter for
listening by a few musical signals,’’ Proc. Spring Meet. Acoust.
Soc. Jpn., pp. 703–704 (2003).

All peer reviewed papers.

Researchers include white-coated and dome-headed types from

Dolby labs
National Institute of Advanced Industrial Science and Technology(Japan)
Tokyo University of Information Sciences,
Shibaura Institute of Technology
Japan Broadcasting Corporation
Media Laboratory S

What was the upshot ?
  • 20ns for deterministic jitter in music
  • 10ns with a pure tone.
  • > 250ns for random jitter
post #26 of 151
Quote:
Originally Posted by tourmaline View Post
The people who know, the ones that on a daily bases mod cdplayers, say that if you use a good reclocking system yoú'll get better transparency/detail.
These would be the same people who sell these clock upgrades?

IMHO, clock upgrades are one of the greatest snake-oil games around, particularly on a measure of cost-to-benefit.
A more accurate clock may technically reduce the jitter however why do they offer these miracle upgrades on mid-high end gear rather than budget CDP's where the benefit should be more noticeable? Something tells me it's got more to do with the motivations and cash reserves of their target market...
post #27 of 151
Quote:
Originally Posted by BigEat View Post
Low is plus or minus 0.1 Parts per million. See for example the specs on the Esoteric Master Clocks.
ppm has nothing to do with jitter. It is a measure of how close to the specified frequency a clock is. See http://www.tentlabs.com/InfoSupport/page34/page34.html. And $4k for a master clock? yeah, right...

Quote:
Originally Posted by tourmaline View Post
Most popular reclocking systems are in terms of 2-3pps. This is far and beyond the popular threshold of 150pps.
What is a pps?

Quote:
Originally Posted by nick_charles View Post
This has been done.

Detection threshold for distortions due to jitter on digital audio
Kaoru Ashihara, Shogo Kiryu, Nobuo Koizumi, Akira Nishimura,
Juro Ohga, Masaki Sawaguchi and Shokichiro Yoshikawa

E. Benjamin and B. Gannon, ‘‘Theoretical and audible effects of
jitter on digital audio quality,’’ Preprint of the 105th AES
Convention, #4826 (1998).

K. Ashihara and S. Kiryu, ‘‘Simulation of sound degradation
due to time jitter on digital audio,’’ J. Acoust. Soc. Jpn. (J), 58,
232–238 (2002).

K. Ashihara and S. Kiryu, ‘‘The maximum permissible size and
detection threshold of time jitter on digital audio,’’ J. Acoust.
Soc. Jpn. (J), 59, 241–249 (2003).

T. Tomizawa, H. Ohtake and J. Ohga, ‘‘Effect of jitter for
listening by a few musical signals,’’ Proc. Spring Meet. Acoust.
Soc. Jpn., pp. 703–704 (2003).

All peer reviewed papers.

Researchers include white-coated and dome-headed types from

Dolby labs
National Institute of Advanced Industrial Science and Technology(Japan)
Tokyo University of Information Sciences,
Shibaura Institute of Technology
Japan Broadcasting Corporation
Media Laboratory S

What was the upshot ?
  • 20ns for deterministic jitter in music
  • 10ns with a pure tone.
  • > 250ns for random jitter
A couple of comments:
  • There have been objections to the testing procedure of the T. Tomizawa, H. Ohtake and J. Ohga study for the lack of control of the test setups (subjects using their own equipment, including DACs via SPDIF, which is known for its jitter inducement on its own).
  • Quoting jitter as a timebase measure (ns, ps) is meaningless without specifying the bandwidth. A starting link for that: DIYHiFi.org &bull; View topic - Any comments on this design (clock with triode)?
  • Hi-Rez Highway. Do some searches and you will find what seems to be a lack of confidence by well known designers (who have been longtime members) in the workings of the AES for a number of decades.
There are still too many people claiming that digital cables sound different, etc. to completely ignore the possibility that jitter could be a real concern. I do think that the analog stages of most digital equipment probably has more effect on its sound than jitter does, but it is something that can be measured, and doesn't have to be obscenely expensive to address (see Tentlabs products, for example).
post #28 of 151
Quote:
Originally Posted by Pars View Post
There are still too many people claiming that digital cables sound different, etc. to completely ignore the possibility that jitter could be a real concern.
Anyone can claim anything, backing it up is somewhat different. As far as I am aware there have been no decent controlled tests that have indicated reliably detectable audible differences between digital cables. This is puzzling as you would think that cable makers would be falling over themselves to demonstrate how their cables are provably better than Brand X cables...

I can point to my own null results comparing several different coax digital cables and toslink cables (or coax vs toslink) into an external DAC, but that is just anecdotal and equally unreliable.
post #29 of 151
Quote:
Originally Posted by nick_charles View Post
Anyone can claim anything, backing it up is somewhat different. As far as I am aware there have been no decent controlled tests that have indicated reliably detectable audible differences between digital cables. This is puzzling as you would think that cable makers would be falling over themselves to demonstrate how their cables are provably better than Brand X cables...
You ever heard of litigation and lawyers? Have you ever seen a single commercial for anything where a known brand makes claims against another brand by name?

Have you seen any decent controlled tests between your hifi equipment and that of other manufacturers? Maybe similar types of tests between the cheapest equipment and the most expensive? Is it not true that your purchases were in the main reliant on what you read in magazines and on the net, but that none of it were the results of decent controlled tests by degree experts?
So you see, you can't be generous with your acceptance of opinions expressed on one type of audio product without any scientific proof, and at the same time dismiss other test results as completely bonkers.
post #30 of 151
Quote:
Originally Posted by nick_charles View Post
`[*]20ns for deterministic jitter in music [*]10ns with a pure tone. [*]> 250ns for random jitter[/LIST]
A couple order of magnitudes higher than a typical CS8414 reciever/DAC ?
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